1. Field of the Invention
The present invention relates to flush tank valve assemblies and more particularly to a replacement valve assembly useful with conventional toilet valve seats.
2. Description of the Prior Art
Hydrostatically closed toilet flush valves have been know in the past. Generally, the sealing interface of such a flush valve with the valve seat normally present in the bottom of the toilet holding tank a source of many problems to the home user. Accordingly, one of the repairs most frequently engaged by a home user is the replacement of such a valve. Generally, such a replacement is called for as a result of the deterioration of the valve body itself and quite often a concurrent corrosive deterioration of the seat. To provide for a convenient repair technique which accommodates both the deterioration of the valve and the valve seat, there have been replacement valves developed in the past which include conically projecting peripheral lips conformed to the conical shape of the seat. Such conically projecting peripheral valve lips distribute the sealing contact over a wide area of the seat and therefore avoids the necessity of resurfacing the seat in order to effect the seal. Use of such conically shaped replacement valves, however, generally always require some means for centering the valve relative the valve seat. When installed by the average home user high accuracy centering techniques are not always possible and, in fact, not desired in a replacement item. To achieve the centering techniques are not always possible, and, in fact, not desired in a replacement item. To achieve the centering function most valve assemblies include a guide which is mounted on the stand pipe or the overflow pipe in the holding tank and through which a shaft is passed which is then connected to the valve. The alignment of this guide is therefore a necessary step in installing the typical prior art replacement valves. Typically, however, both the seat and the stand pipe are formed as one integral structure and if corrosion or deterioration occurs in one part there is usually associated corrosion around the guide mounting making any adjustments therein quite difficult and often leading to the breakage of the standpipe at the connection thereof. A further problem with this prior art arrangement of parts is the rotary articulation of the thrushing lever which does not easily adapted to the vertical up and down motion necessary in the guide. This rotary articulation of the lever therefore produces additional lateral dislocation of the valve during its seating sequence rendering such a replacement valve less effective. To reduce this last mentioned problem there have been several valve seats developed in the past wherein the guide is disposed below the seating plane and a guide rod is provided extending from the lower surface of the valve. Such assemblies, however, have not gained wide acceptance in this field and most valve seats still in use do not include the desired lower guide.